No, the west side of midtown Manhattan hasn’t been taken over by zombies, hobbits, superheroes and monsters. It’s just going to seem that way from now through Sunday.

New York Comic Con opens today, as 100,000-plus attendees – more than a few in lavish, outrageous costumes – descend on Manhattan’s Jacob Javits Center to meet their favorite artists and performers; hear about what’s coming in comics, science fiction, fantasy and horror; and buy all manner of comics, graphic novels, books, video games, toys, DVDs and collectibles.

It’s become the second-biggest such convention in the U.S., after San Diego’s Comic-Con International – and, in the words of Lance Fensterman, who manages the convention, it’s “a big circus.”

“It is a massive celebration of all things pop culture,” Fensterman said by phone earlier this week, as he scrambled to get things ready. “Geeks and pop culture have come of the basement, they’ve gone mainstream.”

About 1,600 exhibitors will be on the convention floor selling and promoting their wares. More than 700 professionals from comics, entertainment and publishing will be appearing – highlighted by panels and autograph sessions featuring the casts of TV shows like “The Walking Dead,” “666 Park Avenue” and “Arrow”; actors from coming films like the remakes of “Carrie” and “Evil Dead”; and pop-culture celebrities like Carrie Fisher from “Star Wars,” Adam West and Burt Ward from the “Batman” TV show, author Anne Rice, filmmaker Guillermo del Toro and many, many others.

There will also be a kick-off concert from the Ben Folds Five; a special anniversary celebration for Spider-Man, who turns 50 this year; costume contests; a day of special events for kids; and “sci-fi speed dating,” seeking to create love matches between like-minded geeks.

Tickets to the convention are sold out, and Fensterman expects attendance of 115,000 or more, up from 105,000 last year.

While a lot of the attendees may be dressed as Avengers, Wookiees, or Japanese anime characters, these geeks spend money: Fensterman estimates the convention’s economic impact on New York City as $60 million to $70 million, with $10 million to $15 million changing hands on the convention floor.

Among other things, the convention gives the two top comics companies, Marvel Comics and DC Entertainment, a major gathering for their fans, artists and writers in the companies’ hometown of New York. “It’s exhausting. It’s a lot easier to go visit a town and leave at the end of the show,” laughs Dan DiDio, DC’s co-publisher.

The convention illustrates how comic-book companies these days have their hands in much more than comics, DiDio said – at the convention, DC will be promoting its efforts in TV, collectibles, video games and other ventures in addition to comics. “We’re looking into so many different areas.”

The growing popularity of events like New York Comic Con, and the growing reach of comics into pop culture, “speaks to the power of the characters - at the end of the day, these stories resonate,” said Axel Alonso, Marvel’s editor-in-chief. The convention ”provides an outlet to see what all the fuss is about.”